The proposed research is directed at continuing our studies aimed at generating cytotoxic lymphocytes in vitro capable of lysing autologous human leukemia cells. Attempts will be made to generate effector cells in mixed leukocyte cultures by culturing remission lymphocytes with a) x-irradiated autologous leukemia cells and x-irradiated allogeneic normal cells or with b) x-irradiated lymphocytes pooled from 20 unrelated normal individuals. In addition, highly purified interferon (IF) and non-toxic polyribonucleotide inducers of IF which render normal lymphocytes cytotoxic for fresh leukemic cells will be tested for their ability to activate patients' remission lymphocytes to lyse autologous malignant cells. Effector cells generated under these various in vitro conditions will be characterized with regards to expression of cell surface antigens by monoclonal antibodies which we have found distinguish cytotoxic T lymphocytes (CTLs) from natural killer (NK) and NK-like cells. We propose to generate large numbers of anti-leukemic effector cells by growing sensitized cells in T cell growth factor (TCGF). As a correlate to the human studies, mouse CTLs will be grown in TCGF and treated for their ability to prevent syngeneic tumor growth in mice. In addition, mouse NK cells activated by non-toxic IF inducers will be tested for anti-leukemia efficacy in vivo.